Preparation of 2-pyrrolidone

ABSTRACT

A process for preparing 2-pyrrolidone which comprises reacting maleic acid or maleic anhydride with hydrogen and ammonia in an aqueous system at a mole ratio of ammonia to acid or anhydride of from 1.0:1 to 1.2:1, at a temperature of from about 200* to about 300*C, at a pressure of from about 1,000 to about 3,000 psig, for a time of about 0.5 to about 8 hours, and in the presence of a catalyst of palladium supported on carbon.

United States Patent Hollstein May 20, 1975 [54] PREPARATION OF Z-PYRROLIDONE 3,448,118 6/1969 Chichery et al. 260/3265 [75] Inventor: Elmer J. l-lollstein, Wilmington, Del.

Primary Examiner-J0seph A. Narcavage [73] Asslgnee' ig zz fi fx g gg g Attorney, Agent, or Firm-George L. Church; Donald p R. Johnson; Paul Lipsitz [22] Filed: Apr. 23, 1973 21 App]. No.1 353,277 [57] ABSTRACT Related US. Application Data A p SS for p 2 rd h roce reparmg -pyrro 1 one w 10 com- [63] fgx sgg ggg of 108376 prises reacting maleic acid or maleic anhydride with hydrogen and' ammonia in an aqueous system at a mole ratio of ammonia to acid or anhydride of from 10:1 to 1221, a a temperature of from about to [58] Field "5 5 FN about 300C, at a pressure of from about 1,000 to about 3,000 psig, for a time of about 0.5 to about 8 [56] References Cited hours, and in the presence of a catalyst of palladium supported on carbon. UNITED STATES PATENTS 3,198,808 8/1965 Himmele et al. 260/3265 3 Claims, 1 Drawing Figure PAIENIED S 3.884.936

EFFECT OF AMMONIA CONCENTRATION ON YIELD OF Z-PYRROLIDONE (nsoucrw: AMMINOLYSIS or MALEIC ANHYDRIDE usms 5% PALLADIUM on CARBON) u 10 O Q a so .J u

so u 2 O 9 O 40 a: o: a

I l l I l I I l 0 0.1 0.8 0.9 1.0 l.| L2 1.3 1.4 1.5 L6 1.1

MOLES AMMONIA PER MOLE MALEIC ANHYDRIDE GE NT 1 PREPARATION or .ZY-P'YRBQLIIDONE RELATED APPLICATION This application is a continuation-in-part of Ser. No. 108,376, filed Jan. 21, 1971 and now abandoned.

The conversion of anhydrides such as maleic anhydride and succinic anhydride to Z-pyrrolidone is known in the art. For example, U.S. Pat. No. 3,080,377 (Liao, assigned to FMC Corp.,'issued Mar.. 5, 1963) discloses that succinic anhydride may be converted to 2- pyrrolidone by reaction for 1 to 8 hours with ammonia (l to 20 moles per mole of anhydride, preferably 2 to 5 moles of liquid ammonia) and at least one mole of hydrogen at 200-300C, at 500 to 5,000 psig, and in the presence of catalysts such as cobalt, nickel, ruthenium, and palladium. Yields of 2-pyrrolidone product are on the order of 30% (with palladium catalyst) to 70% of theory (with Raney cobalt).

U.S. Pat. No. 3,198,808 (l-limmele' et a1, assigned to BASF, issued Aug. 3, 1965) discloses preparation of 2-pyrrolidone from maleic acid and ammonia using a specially prepared sintered oxide catalyst whereby excellent yields are obtained.

U.S. Pat. No. 3,109,005 (Lidov, assigned to I-lalcon International, Inc., issued Oct. 29, 1963) discloses preparation of 2-pyrrolidone and its N-substituted derivatives from maleic anhydride in a solvent system by reaction of hydrogen and 5 .moles of ammonia or suitable amine per mole ofanhydride at 150 to 350C, for 10 to 12 hours at 100 to 30 atmospheres and in the presence of a hydrogenation catalyst such as Raney nickel, Raney cobalt, or palladium or platinum on a support. Yields of product are given as about 65% to 76% of theory. I 1

U.S. Pat. No. 3,448,1 18 (Chickery, assigned to Rhone-Poulenc S.A., issued June 3, 1969) discloses that succinic acid will react with primary amines in various solvent systems (e.g., dioxane, water, tetrahydrofurane, etc.) and in the presence of various catalysts to form N-alkyl-substituted pyrrolidones. Where palladium on charcoal is used as the catalyst in a dioxane system, the yield of product is low,.being 65.5%.

In investigating the process of making 2-pyrrolidone in an aqueous system it has been found that yieldsare generally poor being less than about 60% of theory. Furthermore, although many catalysts and catalyst supma arcjused per mole of maleic acid or anhydride and thatirapid yield fall-off occurs when deviatingfrom this ratio. I The process of the invention is also clearly dependent upon the use of a palladium on carbon catalyst, which may contain from about 1% to 10% (preferably 5%) by weight palladium in the total catalyst-support composition. The amount of catalyst used in the process may vary from about 1% to about 10% by weight of the maleic acid or maleic anhydride, and will preferably be used at 5% by weight. Experiments have shown that the pressure will vary between about 1,000 and 3,000 psig, with a pressure of about 1,700 psig being preferred. Time of reaction may vary from about 0.5 to about 8 I hours, witha preferred reaction time of from about 1.5

to about 2.5 hours, most preferred being about 2 hours.

- If reaction time is maintained for too long, a decrease point a pressure of 1,700 psig is maintained. After holding a temperature for 2 hours thereaction mass .is

in yield is experienced, due, it is believed, to produc-. tion of unwanted by-products, resulting from reactions 1 that the 2-pyrrolidone may enter into.

In order to illustrate the invention the following examples are given:

7 EXAMPLE 1 A series of reactions is carried outfin a rocking 300 ml capaeityautoclave which is charged'with 49g of maleic anhydride, 2.5 g of catalyst'of 5% by fweight'palladium on carbon, 100 ml of water, and varying amounts of 28% aqueous ammonium hydroxide. The

autoclave is closed and charged with hydrogen to 1,600 psig pressure and is then heated to 275C at which cooled, the contents removed and are analyzed. The

7 data obtained is shown in the following table:

ports are suggested for the process, the reaction appears to be highly sensitive to both catalyst metal and its support. It has'now been discovered that in the conversion of maleic acid and maleic anhydride to 2- pyrrolidone in an aqueous system, surprisingly high yields can be obtained by following the process of this invention.

In accord with the invention, 2-pyrrolidone is prehours, and in the presence of a catalyst of palladium supported on carbon.

The amount of ammonia used in the reaction is critical to achieve the high yields capable of the process.

This is clearly shown by the figure which shows that I maximum yield occurs when 1.1 i0.1 moles of ammo- Moles of Ammonia Per Mole of Maleic Anhydride Yield (Mole of 2-Pyrrolidone 3,884,936 3 4 at a pressure from about 1,000 to about 3,000 psig for 2. The process of claim 1 where the temperature is a time of about 0.5 to about 8 hours, and in the presabout 275C, pressure is about 1,700 psig and reaction ence of from about 1% to about 10% by weight of said time is about 2 hours. acid or anhydride of a catalyst of palladium supported 3. The process of claim 2 with maleic anhydride.

on carbon. 5 

1. A PROCESS FOR PREPARING 2-PYRROLIDONE WHICH COMPRISES REACTING MALEIC ACID OR MALEIC AHYDRIDE WITH HYDROGEN AND AMMONIA IN AN AQUEOUS SYSTEM AT A MOLE RATIO OF AMMONIA TO ACID OR ANHYDRIDE OF FROM 1.0:1 TO 1.2:1 AT A TEMPERATURE FROM ABOUT 200* TO ABOUT 300*C, AT A PRESSURE FROM ABOUT 1,000 TO ABOUT 3,000 PSIG FOR A TIME OF ABOUT 0.5 TO ABOUT 8 HOURS, AND IN THE PRESENCE OF FROM ABOUT 1% TO ABOUT 10% BY WEIGHT OF SAID ACID OR ANHYDRIDE OF A CATALYST OF PALLADIUM SUPPORTED ON CARBON.
 2. The proceSs of claim 1 where the temperature is about 275*C, pressure is about 1,700 psig and reaction time is about 2 hours.
 3. The process of claim 2 with maleic anhydride. 